Terrin Westfall is the younger brother of Chaol Westfall and (because Chaol abdicated his title) the heir of the Adarlanian duchy of Anielle.
Lord Westfall describes Terrin as "all gangly limbs and awkward angles" due to genetics from Terrin's mother.
As Terrin never physically appears in the novels, little is known about his personality. His father, Lord Westfall, believes that he is weak and unfit to rule Anielle, claiming he is a scholar and not a warrior. However, he does exhibit a moment of bravery when Chaol is thrown from the keep above Silver Lake upon advocating his title, bracing their father's anger by trying to go to an injured Chaol.
- Tower of Dawn, page 277